To complete a well, one or more formation zones adjacent the wellbore are perforated to allow fluid from the formation zones to flow into the well for production to the surface. Perforations are typically created by perforating gun strings that are lowered to desired intervals in the wellbore. When fired, perforating guns extend perforations into the surrounding formation.
In producing fluids from a reservoir in a formation, particulates such as sand may be produced with reservoir fluids. Such particulates may damage the well and significantly reduce production and life of the well. Formation fluids containing particulates may act as an abrasive that wears and erodes downhole components, such as tubing. In addition, production of particulates such as sand may create voids in the formation behind the casing which may result in buckling of or other damage to the casing. Moreover, particulates produced to the surface are waste products requiring disposal, which may be costly.
Various methods and devices for reducing or eliminating sand and other particulate production have been developed. Gravel packing of the formation is a popular technique for controlling sand production. Although there are variations, gravel packing essentially involves placing a sand screen around the section of the production string containing the production inlets. This section of the production string is aligned with the perforations. A slurry of gravel in a viscous transport fluid is pumped into the annulus between the sand screen and the casing. The deposited gravel blocks the formation particulates, such as sand, from flowing into the production tubing. However, formation fluids are allowed to enter the production string for flow to the well surface.
In some scenarios, such as when relatively long formations are being gravel packed, it may be desirable to employ zonal isolation to define multiple zones that are isolated from each other. Conventionally, the isolation used with sand control equipment includes cup packers in cased hole applications. However, use of cup packers reduces flexibility in how zones can be isolated.